通过对上海CY孔晚第四纪沉积样品的孢粉和藻类分析,从长江三角洲地区古土壤层中分析出较丰富的孢粉、藻类化石。共鉴定得孢粉、藻类55个科属,根据其组合特征,进一步讨论了古土壤层形成时的环境,为长江三角洲地区古土壤成因研究提供了生物化石依据。研究结果表明,古土壤的形成主要受到水流作用。古土壤层中环纹藻与陆生草本植物花粉含量互为消长的孢粉、藻类组合序列,证明了该地区古土壤形成期间曾经历水泛和水退的环境交替。水泛时期环纹藻大量发育,而到了水退期,暴露的陆区发育陆生草本植物,这也反映了本区古土壤形成时环境条件多变,造成了古土壤成土特征的多期性。化石组合中海水生沟鞭藻以低含量存在,表明CY孔所在地区在古土壤母质沉积时曾受到海水影响。 Based on the analysis of sporo-pollen and algae from the Quaternary sedimentary samples of the late CY pore in Shanghai, abundant sporopollen and algal fossils were analyzed from the paleosol layer in the Yangtze River Delta. A total of 55 families of sporopollen and algae were identified. According to their assemblage characteristics, the environment during the formation of palaeosol layer was further discussed, which provided biological fossil basis for the study of paleosol in the Yangtze River Delta. The results show that the formation of ancient soil is mainly affected by water flow. The sequence of pollen assemblages and algae in which the pollen content of ring-shaped algae and terrestrial herbaceous plants exuded from each other in the ancient soil layer proved the alternation of the environment which experienced the flood and water retreat during the formation of ancient soils in the area. During the flood period, C. albicans was extensively developed. However, by the time of water refolding, terrestrial herbaceous plants were developed in the exposed land areas. This also reflects the change of the environmental conditions during the formation of ancient soils in this area, resulting in the multi-period Sex. The low abundance of marine aquatic dinoflagellates in the fossil assemblages suggests that the area where the pores of the CY locates was influenced by the seawater during the deposition of the palaeosol.